U.S. patent number 6,105,695 [Application Number 09/220,493] was granted by the patent office on 2000-08-22 for multifunction automated crawling system.
This patent grant is currently assigned to California Institute of Technology. Invention is credited to Paul Gregory Backes, Yoseph Bar-Cohen, Benjamin Joffe.
United States Patent |
6,105,695 |
Bar-Cohen , et al. |
August 22, 2000 |
Multifunction automated crawling system
Abstract
The present invention is an automated crawling robot system
including a platform, a first leg assembly, a second leg assembly,
first and second rails attached to the platform, and an onboard
electronic computer controller. The first leg assembly has an
intermittent coupling device and the second leg assembly has an
intermittent coupling device for intermittently coupling the
respective first and second leg assemblies to a particular object.
The first and second leg assemblies are slidably coupled to the
rail assembly and are slidably driven by motors to thereby allow
linear movement. In addition, the first leg assembly is rotary
driven by a rotary motor to thereby provide rotary motion relative
to the platform. To effectuate motion, the intermittent coupling
devices of the first and second leg assemblies alternately couple
the respective first and second leg assemblies to an object. This
motion is done while simultaneously moving one of the leg
assemblies linearly in the desired direction and preparing the next
step. This arrangement allows the crawler of the present invention
to traverse an object in a range of motion covering 360
degrees.
Inventors: |
Bar-Cohen; Yoseph (Seal Beach,
CA), Joffe; Benjamin (Chatsworth, CA), Backes; Paul
Gregory (La Cresenta, CA) |
Assignee: |
California Institute of
Technology (Pasadena, CA)
|
Family
ID: |
24775562 |
Appl.
No.: |
09/220,493 |
Filed: |
December 22, 1998 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
691202 |
Aug 1, 1996 |
5890553 |
|
|
|
Current U.S.
Class: |
180/8.5;
901/1 |
Current CPC
Class: |
B62D
57/02 (20130101); B62D 57/024 (20130101); Y10S
180/901 (20130101) |
Current International
Class: |
B62D
57/00 (20060101); B62D 57/02 (20060101); B62D
57/024 (20060101); B62D 057/032 () |
Field of
Search: |
;180/8.1,8.5,8.6,164
;901/1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Swann; J. J.
Assistant Examiner: Shriver; J. Allen
Attorney, Agent or Firm: Michaelson & Wallace
Parent Case Text
This is a divisional of application Ser. No. 08/691,202, filed Aug.
1, 1996 Ser. No. 5,890,553.
Claims
What is claimed is:
1. An automated crawling robot system for traversing about an
object with a range of motion of 360 degrees, comprising:
a platform;
a first leg assembly slidably coupled to the platform and rotatably
coupled to the platform and having an intermittent coupling device
for intermittently coupling the first leg assembly to the object
and a first ball screw and receiver system;
a second leg assembly slidably coupled to the platform and having
an intermittent coupling device for intermittently coupling the
second leg assembly to the object and a second ball screw and
receiver system;
a motor for driving the first and second ball screw and receiver
systems;
wherein said first ball screw is located opposite the second ball
screw, has an opposite pitch from the second ball screw, and is
attached to the second ball screw so that the motor can drive both
ball screws; and
a rotary motor for rotatably traversing the second leg assembly
relative to the platform.
2. The invention as set forth in claim 1, further comprising an
onboard computer controller for controlling the movement of the
robot with preprogrammed instructions and with remote commands.
3. The invention as set forth in claim 1, further comprising a
carrying area for carrying data gathering equipment and for
transporting materials.
4. The invention as set forth in claim 1, wherein said platform
further comprises a rail system, wherein said first and second leg
assemblies slidably traverse about said rail system.
5. The invention as set forth in claim 1, wherein said rotary motor
is a low mass compact ultrasonic motor.
6. The invention as set forth in claim 1, wherein said intermittent
coupling device is a magnetic device having intermittently
activated solenoids.
7. The invention as set forth in claim 1, wherein said intermittent
coupling device is a plurality of suction cups.
8. The invention as set forth in claim 7, wherein said plurality of
suction cups are a plurality of vacuum cups, each having a separate
vacuum pump and a separate air cylinder coupled to it, wherein each
vacuum pump provides each vacuum cup with a vacuum source
independent of the other vacuum cups.
9. The invention as set forth in claim 8, wherein said vacuum pumps
are venturi vacuum pumps.
10. The invention as set forth in claim 8, wherein said vacuum
pumps and said air cylinders are coupled to a standard air
compressor for providing each vacuum pump and each air cylinder
with air pressures.
11. The invention as set forth in claim 10, further comprising
flexible tubing for providing a means for transferring the air
pressure from the air compressor to each vacuum pump and each air
cylinder.
Description
BACKGROUND OF THE INVENTION
1. Origin of the Invention
The invention described herein was made in the performance of work
under a NASA contract, and is subject to the provisions of Public
Law 96-517 (35 USC 202) in which the contractor has elected to
retain title.
2. Field of the Invention
The present invention relates to automated robot systems, and in
particular to an automated crawling robot with multifunctional
purposes, such as performing labor intensive tasks and/or dangerous
field tasks.
3. Related Art
Automated robotic crawling systems are needed to perform labor
intensive and dangerous field tasks in the areas of structures
inspection/repair. Typical tasks for crawling systems include
inspection of repairs of aircraft, detection of cracks, dents,
corrosion, impact damage, delaminations, fire damage, porosity, and
other flaws in structures. Also, crawling systems are needed for
the performance of specific tasks, such as hazardous material
handling, including toxic materials and bombs.
Current crawling systems include, for instance, a tank crawler and
a cruciform crawler. The tank crawler has a body with a continuous
belt having a vacuum pad with numerous suckers. Each sucker is
connected to an air duct inside the continuous belt and has a
mechanical valve. For each sucker, the valve opens mechanically
when the sucker touches the surface of a particular object to
thereby allow the sucker to cling to the surface. A motor, timing
belt, and timing pulley are located within the body and operate to
turn the continuous belt to provide the tank crawler with secure
movement over a surface of an object.
The cruciform crawler comprises a horizontal spine and vertical
bridges. Both the horizontal spine and the bridges have plural
suction cups for secure coupling to a particular object. In order
to effectuate movement of the cruciform crawler, the vertical
bridges are moved forward while the suction cups of the horizontal
spine are secured to an object. Next, the spine is moved forward
while the suction cups of the vertical bridges are secured to
complete one cycle. Each cycle produces linear movement of the
cruciform crawler across an object.
Although the tank crawler has proven useful for certain tasks, the
tank crawler is cumbersome, is large and bulky, and has limited
movement. For example, the tank crawler cannot perform difficult
maneuvers and does not provide a full range of motion. Thus, the
limited motion of the tank crawler, as well as the cumbersome,
bulky, and large size of the tank crawler, prohibits it from
performing certain important tasks. In addition, steering the tank
causes wear to the suckers which are attached to the belt.
With regard to the cruciform crawler, the movement of the cruciform
crawler is limited to mainly linear movement and not sharp angular
maneuvers. Consequently, does not allow a full 360 degree range of
motion over a point. Thus, the limited motion of the cruciform
crawler prohibits it from performing certain important tasks. In
addition, similar to the suckers of the tank crawler, the suckers
are subject to wear during maneuver.
Many current crawling systems are heavy, are complex to operate and
maneuver, have high power requirements involved with preparation
time between steps and have low payload/crawler weight ratio.
Moreover, since these current crawling systems are designed for
specific tasks, they have limited uses and cannot be utilized for a
variety of tasks. Further, existing crawling systems do not have
carrying areas for carrying observation cameras, sensors and sensor
manipulation devices, and data gathering equipment such as computer
processors, for transporting hazardous materials, for retrieving
items and objects, etc.
Therefore, what is needed is a portable, user friendly automated
robotic crawling system that can move rapidly over large areas with
a full range of motion, perform a wide variety of tasks in all
types of environments, including hostile environments, and access
difficult to reach areas. What is further needed is a crawling
system that has a carrying area for carrying observation cameras,
sensors and sensor manipulation devices, and data gathering
equipment such as computer processors, for transporting hazardous
materials, and for retrieving items and objects.
Whatever the merits of the above mentioned systems and methods,
they do not achieve the benefits of the present invention.
SUMMARY OF THE INVENTION
To overcome the limitations in the prior art described above, and
to overcome other limitations that will become apparent upon
reading and understanding the present specification, the present
invention is an automated crawling robot system with
multifunctional purposes.
The automated crawling system includes a platform, a first leg
assembly, a second leg assembly, first and second guiding rails
attached to the platform, and an onboard electronic computer
controller. The onboard computer can control the movement of the
robot and can have preprogrammed instructions or can accept remote
commands. The first and second leg assemblies have intermittent
coupling devices for intermittently coupling the respective first
and second leg assemblies to a particular object.
The first leg assembly is slidably coupled to the first rail and is
slidably driven by a first motor to thereby effectuate linear
movement of the first leg assembly relative to the platform.
Similarly, the second leg assembly is slidably coupled to the
second rail and is slidably driven by
a second motor to thereby effectuate linear movement of the second
leg assembly relative to the platform. In addition, the first leg
assembly is rotatably coupled to the platform and is rotary driven
by a rotary motor to thereby provide rotary motion to the first leg
assembly relative to the platform.
The intermittent coupling devices of the first and second leg
assemblies alternately couple the respective first and second leg
assemblies to an object. Specifically, the crawler of the present
invention effectuates movement with repetitive cyclic actions. For
each cycle, first the intermittent coupling device of the first leg
assembly is initially coupled to a particular object while the
intermittent coupling device of the second leg assembly remains
uncoupled to the object. Next, the second assembly is linearly
traversed by the second motor.
Also, it should be noted that the first leg assembly can be
linearly traversed by the first motor or rotatably traversed by the
rotary motor either separately or simultaneously. This arrangement
allows the crawler of the present invention to traverse an object
in a range of motion covering 360 degrees.
Another feature of the present invention is the carrying area for
carrying observation cameras, sensors and sensor manipulation
devices, and data gathering equipment such as computer processors,
for transporting hazardous materials, and for retrieving items and
objects. Another feature of the present invention is its
intermittent coupling devices which allow the automated crawling
system to traverse an object rapidly. Yet another feature is
simultaneous preparation of a subsequent step while a previous step
is being completed.
An advantage of the automated crawling system of the present
invention is the ability to perform multifunctional operations.
Another advantage of the automated crawling system of the present
invention is that it is portable, can obtain rapid movements over
large areas, and can perform a wide variety of tasks in all types
of environments, including hostile environments and environments
with difficult to reach areas. Yet another advantage of the present
invention is that it has low power requirements and has a high
payload/crawler weight ratio. Yet another advantage is speedy
traversal due to efficient time management.
The foregoing and still further features and advantages of the
present invention as well as a more complete understanding thereof
will be made apparent from a study of the following detailed
description of the invention in connection with the accompanying
drawings and appended claims .
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings in which like reference numbers
represent corresponding parts throughout:
FIG. 1 is a perspective view of the automated crawling system of
the present invention;
FIG. 2 is a bottom view of the automated crawling system of the
present invention;
FIG. 3 is a cross sectional side view of the automated crawling
system of the present invention;
FIG. 4 is a bottom view of the first leg of the automated crawling
system at its front-most extreme position and the second leg at its
rear-most extreme position;
FIG. 5 is a bottom view of the first leg of the automated crawling
system at its rear-most extreme position and the second leg at its
front-most extreme position;
FIGS. 6-12 illustrate sequential movement of the automated crawling
system from point A to point B;
FIG. 13 is an alternative embodiment of the present invention;
and
FIGS. 14-15 illustrate sequential movement of the automated
crawling system of FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following description of the preferred embodiment, reference
is made to the accompanying drawings which form a part hereof, and
in which is shown by way of illustration a specific embodiment in
which the invention may be practiced. It is to be understood that
other embodiments may be utilized and structural changes may be
made without departing from the scope of the present invention.
FIG. 1 is a perspective view of the automated crawling system of
the present invention. FIG. 2 is a bottom view of the automated
crawling system of the present invention.
Structural Components
The present invention is an automated crawling system 10 including
a platform 12, such as a flat platform, a first leg assembly 14, a
second leg assembly 16, a rail assembly 18, and an onboard
electronic computer controller 21. The carrying area 19 can carry
observation cameras, sensors and sensor manipulation devices, and
data gathering equipment such as computer processors, and can
transport hazardous materials, and can retrieve items and objects.
The onboard computer controller 21 can control the movement of the
robot with preprogrammed instructions or can accept remote
commands.
The rail assembly 18 comprises a first rail 20, a second rail 22,
and rail supports 24 located at an end 26, 28 of each rail 20, 22,
respectively. The first and second rails 20, 22 are attached or
mounted to the platform 12 and extend along opposite longsides 30,
32 of the platform 12 of the crawler 10.
The first leg assembly 14 comprises a mounting disc 34, such as a
circular flat disc, a first bracket 36, and an intermittent
coupling device 38, such as a plurality of vacuum cups 40. The
intermittent coupling device 38 can comprise any mechanism suitable
for intermittent coupling to a particular object (described in
detail in the Operation section below). For example, an
intermittent coupling device with a vacuum cup arrangement 40, as
shown in FIG. 1, is suitable for intermittent coupling to a surface
of a particular object and will be described hereafter as a working
example. However, for ferromagnetic objects or objects with
ferromagnetic surfaces, a magnetic device having intermittent
activated solenoids can be utilized as the intermittent coupling
device.
The mounting disc 34 is attached to the first bracket 36. The first
bracket 36 preferably has two strips 46, 48 extending outwardly
from the platform 12. A plurality of sliders 50 are preferably
attached to each outside portion of the strips 46, 48 of the first
bracket 36. Each slider 50 is also slidably coupled to one of the
rails 20, 22 of the rail assembly 18. The sliders 50 provide the
first bracket 36 with freedom of linear movement relative to the
platform 12.
The second leg assembly 16 comprises a second bracket 52 and an
intermittent coupling device 54 similar to the intermittent
coupling device 38 of FIG. 1, which is preferably a plurality of
vacuum cups 76 (similar to vacuum cups 40 of FIG. 2). The second
bracket 52 is preferably a "U" shaped bracket with a topside
surface and opposite inside surfaces. The second bracket 52 has a
plurality of sliders 56 (similar to sliders 50 of FIG. 2)
preferably attached to each inside surface of the second bracket
52. Each slider 56 is also slidably coupled to one of the rails 20,
22 of the rail assembly 18.
A first motor 58, which can be a conventional electric motor, is
rigidly attached to the platform 12. The first motor 58 has a ball
screw shaft 62 coupled to a first receiver 64 which can be attached
to or integral with the first bracket 36. Also, the first motor 58
can have encoders (not shown) to determine the position of
traversal of the first bracket 36. Since the first bracket 36 is
slidably coupled to the platform 12 and the first receiver 64 is
rigidly attached the first bracket 36, the first motor 58 and the
ball screw shaft 62 provide the first bracket 36 with linear
motion, relative to the platform 12, in either a forward or reverse
direction (described in detail in the Operation section below).
Similar to the first motor 58 configuration, a second motor 66 is
rigidly attached to the platform 12. The second motor 66 has a ball
screw shaft 67 coupled to a second receiver 68 which can be
attached to or integral with the second bracket 52. Also, the
second motor 66 can have encoders (not shown) to determine the
position of traversal of the second bracket 52. Since the second
bracket 52 is slidably coupled to the platform 12 and the second
receiver 68 is rigidly attached the second bracket 52, the second
motor 66 and the ball screw shaft 67 provide the second bracket 52
with linear motion, relative to the platform 12, in either a
forward or reverse direction (described in detail in the Operation
section below).
FIG. 3 is a cross sectional side view of the automated crawling
system of the present invention of FIG. 2. A rotary motor 70, which
can be an ultrasonic motor, such as a low mass compact ultrasonic
motor, or other type of rotary motor, is preferably attached to the
first bracket 36 and is coupled to the mounting disc 34 via a shaft
71. The rotary motor 70 provides the mounting disc 34 with rotary
motion in either a clockwise or counter clockwise direction.
Referring to FIG. 3 along with FIGS. 1 and 2, the vacuum cups 40 of
the first leg assembly 14 are preferably attached to the mounting
disc 34 so that they protrude from the mounting disc 34 as shown in
FIG. 3. Each vacuum cup 40 has a separate vacuum pump 72 and a
separate air cylinder 74 coupled to it and attached to the mounting
disc 34. Each vacuum pump 72 provides such vacuum cup with a vacuum
source independent of the other vacuum cups; such as a venturi
vacuum pump.
The vacuum pumps 72 and the air cylinders 74 are also coupled to a
standard air compressor (not shown) for providing each vacuum pump
72 and air cylinder 74 with air pressures preferably ranging from
70-120 psi. Flexible tubing 75, such as polyethylene tubing, PVC
tubing, or the like, provides a means for transferring the air
pressure from the air compressor to each vacuum pump 72 and each
air cylinder 74.
The vacuum cups 76 of the second leg assembly 16 are preferably
attached to the second bracket 52 so that they protrude from the
topside surface of the second bracket 54. Similar to the vacuum
cups 40 of the first leg assembly 14, each vacuum cup 76 of the
second leg assembly 16 has a separate vacuum pump 84 coupled to it
and attached to the second bracket 52. Also, each vacuum cup 76 of
the second leg assembly 16 has a separate air cylinder 86 coupled
to it and mounted behind each vacuum cup 76.
In addition, similar to the vacuum pumps 72 of the first leg
assembly 14, each vacuum pump 84 of the second assembly 16 is
preferably a venturi vacuum pump. Moreover, the air cylinders 86
and the vacuum pumps 84 of the second assembly 16 are coupled to
the same air compressor (not shown) as the vacuum pumps 52 and air
cylinders 54 of the first leg assembly 14. Flexible tubing 88
similar to flexible tubing 75 is used with the second leg assembly
16. As stated above, it should be noted that the intermittent
coupling devices 38, 54 can be any device suitable for coupling to
an object is not limited to being a vacuum pump device.
FIG. 4 is a bottom view of the first leg assembly and the second
leg assembly of the automated crawling system of the present
invention at their front-most extreme positions, respectively. FIG.
5 is a bottom view of the first leg assembly and the second leg
assembly of the automated crawling system of the present invention
at their rear-most extreme positions, respectively.
In addition, the rotary motor 70 allows movement of the first leg
assembly 14 rotationally along the shaft 71, in the direction
indicated by arrow 94 as shown in FIG. 3. A detailed description of
the operation and the interaction of the components of the crawler
10 will be discussed in the Operation section below.
Operation
FIGS. 6-12 illustrate sequential movement of the automated crawling
system from point A to point B to point C along x and y axes and
around a z axis. The onboard computer controller 21 can control the
movement of the robot with preprogrammed instructions or can accept
remote commands. The crawler of the present invention effectuates
movement with repetitive cyclic actions.
FIGS. 6-9 illustrate one cycle of linear movement and FIGS. 10-12
illustrate rotational movement. For each cycle, first referring to
FIG. 6, the intermittent coupling device 54 of the second leg
assembly 16 is initially coupled (as indicated by shading of the
intermittent coupling device 54 of FIG. 6) to a particular object
100. During this, the intermittent coupling device 38 of the first
leg assembly 14 remains uncoupled (as indicated by non-shading of
the intermittent coupling device 38 of FIG. 6) to the object
100.
Next, as shown in FIG. 7, the second leg assembly 16 is linearly
traversed by the second motor 66. Linear movement of the platform
12 relative to the object 100, as indicated by arrow 102, is
accomplished by operating the second motor 66. As the second motor
66 operates, the ball screw shaft 67 traverses along the second
receiver 68. After traversal, the second leg assembly 16 is
uncoupled from the object 100.
Third, as shown in FIG. 8, the intermittent coupling device 38 of
the first leg assembly 14 is coupled (as indicated by shading of
the intermittent coupling device 38 of FIG. 7) to the object 100
while the intermittent coupling device 54 of the second leg
assembly 16 remains uncoupled (as indicated by non-shading of the
intermittent coupling device 54 of FIG. 7) to the object 100. It
should be noted that while the previous step is being completed,
the crawler 10 prepares a subsequent step for movement by operating
the first motor 58. One of the leg assemblies 14 or 16, move
relative to the object 100.
Fourth, as shown in FIG. 9 and similar to the movement of the
second leg assembly 16, linear movement of the platform 12 relative
to the object 100, as indicated by arrow 104, is accomplished by
operating the first motor 58. As the first motor 58 operates, the
ball screw shaft 62 traverses along the first receiver 64. Since
the first receiver 64 is rigidly attached to the second bracket 52,
the first motor 58 is rigidly attached to the platform 12, and the
platform 12 is slidably attached to the second bracket 52 via the
rails 20, 22, linear movement (forward or reverse) of the second
bracket 52 along the rails 20, 22 relative to the platform 12 is
accomplished.
Further, as shown in FIG. 10, the crawler of the present invention
can rotationally change direction of movement with a 360 degree
range of motion. For example, first the intermittent coupling
device 38 of the first leg assembly 14 is coupled (indicated by
shading of the intermittent coupling device 38 of FIG. 10) to the
object 100. Next, the intermittent coupling device 54 of the second
leg assembly 16 is uncoupled (indicated by non-shading of the
intermittent coupling device 54 of FIG. 7) to the object 100.
The rotary motor 70 is then operated for providing the mounting
disc 34 with rotary motion in either a clockwise, as indicated by
arrow 106 to reach point C, or counter clockwise direction. Since
the rotary motor 70 provides relative rotational motion between the
mounting disc 34 and the first bracket 36, and the first bracket 36
is attached to the platform 12, the platform 12 rotates during
operation of the rotary motor 70, with a range of motion of 360
degrees.
After the desired rotation of the crawler is achieved, the crawler
can be linearly traversed by repeating cycles of movement as
discussed above. As shown in FIG. 11, the intermittent coupling
device 54 of the second leg assembly 16 is again coupled (as
indicated by shading of the intermittent coupling device 54 of FIG.
11) to the object 100. During this, the intermittent coupling
device 38 of the first leg assembly 14 is uncoupled (as indicated
by non-shading of the intermittent coupling device 38 of FIG. 11)
to the object 100. Next, as shown in FIG. 12, the second leg
assembly 16 is linearly traversed, as indicated by arrow 108, by
the second motor 66 in accordance with the above discussion.
FIG. 13 is an alternative embodiment of the present invention.
Alternatively, a more compact crawler is disclosed with a second
leg assembly 110 having a compact bracket 112 slidably coupled to a
platform 114. The crawler also includes a motor 116. The second leg
assembly has a second ball screw 118 and a second receiver 120
operated by the motor 116
and physically located on one side of the platform 114. The crawler
further includes a first leg assembly 122 having a compact bracket
124 slidably coupled to the platform 114 and a first ball screw 126
and a first receiver 128 operated by the motor 116 and physically
located opposite the second ball screw 118. The first ball screw
126 of the first leg assembly 122 has an opposite pitch from the
second ball screw 118 (i.e., right versus left hand threads) and is
attached to the second ball screw 118 so that the motor 116 drives
both ball screws 118, 126.
Linear movement of the platform 114 of FIG. 13 via the leg
assemblies 110, 124 is similar to the linear movement of the
platform 12 of FIGS. 6-12 with the exception of using only one
motor for linear motion. Specifically, the one motor 116 turns both
the first ball screw 126 and the second ball screw 118. Thus, the
crawler is more compact and has fewer motors.
For instance, as shown in FIG. 14, the first leg assembly 14 is
coupled (as indicated by shading of the first leg assembly 122 of
FIG. 14) to an object 130 while the second leg assembly 110 remains
uncoupled (as indicated by non-shading of the second leg assembly
110 of FIG. 14) to the object 130. Next, as shown in FIG. 15,
linear movement of the crawler as indicated by arrow 132, is
accomplished by operating the motor 116.
The foregoing description of the preferred embodiment of the
invention has been presented for the purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise form disclosed. Many modifications and
variations are possible in light of the above teaching. It is
intended that the scope of the invention be limited not by this
detailed description, but rather by the claims appended hereto.
* * * * *